Circuit board, manufacturing method and display module

Abstract

The application discloses a circuit board, a manufacturing method and a display module. The circuit board of one embodiment comprises a substrate layer, a plurality of trace layers, a pin layer and a heat dissipation structure arranged in sequence. The heat dissipation structure comprises a heat dissipation cavity penetrating through part of the plurality of trace layers, a first through hole, a second through hole, and the heat dissipation cavity has a first end and a second end. The first end and the second end are arranged opposite to the projection of the substrate layer. Based on the heat dissipation structure design, the heat dissipation cavity, the first through hole and the second through hole constitute a heat dissipation passage capable of exchanging air with the outside air, thereby realizing heat dissipation of the heat dissipation structure and improving the display of the display panel caused by the heat conduction of the electronic components to the display panel.

Description

Circuit board, manufacturing method and display module Technical Field

[0001] This invention relates to the field of display technology. More specifically, it relates to a circuit board, a manufacturing method, and a display module. Background Technology

[0002] Automotive displays and in-flight entertainment displays are indispensable devices in modern transportation. However, compared to the OLED (organic light-emitting diode) applications in traditional consumer mobile phones, automotive and in-flight entertainment displays have more stringent requirements, such as harsher working environments, higher security, longer working hours, and more functional integration. As a result, related display products may exhibit localized yellow spots and display defects. Summary of the Invention

[0003] The purpose of this invention is to provide a circuit board, a manufacturing method, and a display module to solve at least one of the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] The first aspect of the present invention provides a circuit board, the circuit board comprising a base layer, a plurality of trace layers and a pin layer stacked sequentially, the circuit board further comprising a heat dissipation structure, the heat dissipation structure comprising:

[0006] A heat dissipation cavity that extends through at least a portion of the multiple wiring layers;

[0007] A first via, penetrating the pin layer and extending in a direction opposite to the stacking direction, connects to a first end of the heat dissipation cavity; and

[0008] The second via penetrates the pin layer and extends in a direction opposite to the stacking direction to communicate with the second end of the heat dissipation cavity. The first end and the second end of the heat dissipation cavity are positioned opposite each other on the orthographic projection of the substrate layer.

[0009] Optionally, the heat dissipation structure further includes a first connecting channel connecting the first guide hole and the first end of the heat dissipation cavity. The first connecting channel penetrates at least a portion of the wiring layers corresponding to the heat dissipation cavity, and the number of wiring layers penetrated by the first connecting channel is less than the number of wiring layers penetrated by the heat dissipation cavity.

[0010] Optionally, the heat dissipation structure further includes a second connecting channel connecting the second guide hole and the second end of the heat dissipation cavity. The second connecting channel penetrates at least a portion of the wiring layers corresponding to the heat dissipation cavity, and the number of wiring layers penetrated by the second connecting channel is less than the number of wiring layers penetrated by the heat dissipation cavity.

[0011] Optionally, the heat dissipation structure further includes a heat insulation material filling the heat dissipation cavity, the first guide hole, and the second guide hole.

[0012] When the heat dissipation structure further includes a first connecting channel, the heat insulation material is also filled in the first connecting channel;

[0013] and / or

[0014] When the heat dissipation structure further includes a second connecting channel, the heat insulation material is also filled in the second connecting channel.

[0015] Optionally, the heat dissipation structure further includes

[0016] The first guide tube is connected to the first guide hole;

[0017] The second guide tube is connected to the second guide hole;

[0018] The heat dissipation fluid filling the heat dissipation cavity; and

[0019] A heat dissipation driving unit connecting the first guide pipe and the second guide pipe is used to drive the heat dissipation fluid to flow in the return structure formed by the heat dissipation cavity, the first guide hole, the first guide pipe, the second guide pipe and the second guide hole.

[0020] Optionally, the pin layer includes multiple pins;

[0021] The routing layer includes a connection layer, which includes multiple connection lines that are respectively connected to the pins of the pin layer.

[0022] The through-hole formed by the heat dissipation structure in the connecting line layer avoids the connecting line.

[0023] Optionally, the routing layer further includes:

[0024] A shielding layer disposed between adjacent pin layers and trace layers, and / or disposed between adjacent interconnect layers, and

[0025] A grounding layer is set between two adjacent film layers.

[0026] Wherein, the through hole formed by the heat dissipation structure penetrating the shielding layer avoids the shielding metal of the shielding layer;

[0027] The through-hole formed by the heat dissipation structure penetrating the grounding layer avoids the grounding wire of the grounding layer.

[0028] Optionally, the first guide hole may be a plurality of air inlets, arranged sequentially along the first direction.

[0029] The second guide hole consists of multiple vent holes, arranged sequentially along the first direction.

[0030] The first guide hole and the second guide hole are respectively disposed on opposite sides of the projection boundary of the heat dissipation cavity on the substrate layer.

[0031] Optionally, the pin is connected to an electronic component fixed on the surface of the pin layer away from the substrate layer;

[0032] The orthographic projection of the first via on the substrate and the orthographic projection of the second via on the substrate are located outside the orthographic projection of the electronic component on the substrate.

[0033] A second aspect of the present invention provides a display module, the display module comprising:

[0034] Display panel;

[0035] A circuit board of the first aspect of the present invention, bonded to the display panel, the circuit board being fixed to the non-light-emitting side of the display panel, the pin layer being farther away from the display panel than the substrate layer; and

[0036] Multiple electronic components are disposed on the display panel, and each pin of the electronic components is connected to the pin of the pin layer.

[0037] Optionally, the electronic components include one or more of the following: a timing controller, a signal bridge chip, a memory chip, a power management chip, a thin-film driver transistor, or a crystal oscillator.

[0038] Wherein, the orthographic projection of the heat dissipation cavity onto the substrate layer covers the orthographic projection of one of the electronic components onto the substrate layer or the combined projection formed by superimposing the orthographic projections of multiple components onto the substrate layer.

[0039] Optionally, the circuit board is connected to a trace end located at one end of the display panel via a bonding part and folded to the non-light-emitting side of the display panel.

[0040] The first guide hole is an air inlet, the second guide hole is an exhaust outlet, and the second guide hole is farther away from the wiring end of the display panel than the first guide hole.

[0041] A third aspect of the present invention provides a method for manufacturing a circuit board, the method comprising:

[0042] Multiple overlapping wiring layers are sequentially formed on the base layer;

[0043] The wiring layers are patterned to form a heat dissipation cavity that extends at least through a portion of the wiring layers;

[0044] A pin layer is formed on the side of the trace layer away from the substrate layer;

[0045] The pin layer and the trace layer are patterned, and the patterned vias are extended to communicate with the first end of the heat dissipation cavity to form a first via.

[0046] The pin layer and the trace layer are patterned, and the patterned vias are extended to communicate with the second end of the heat dissipation cavity to form a second via. The first end and the second end of the heat dissipation cavity are positioned opposite each other on the orthographic projection of the substrate layer.

[0047] The first guide hole, the second guide hole, and the heat dissipation cavity form a heat dissipation structure.

[0048] The beneficial effects of this invention are as follows:

[0049] Based on the heat dissipation structure design of this embodiment, the heat dissipation cavity, the first guide hole and the second guide hole constitute a heat dissipation path that can exchange airflow with the outside gas, thereby realizing the heat dissipation of the heat dissipation structure. The circuit board of this embodiment does not sacrifice the overall space and there is no problem of external bonding of thermally conductive materials. The internal structure of the circuit board is designed directly to improve the display failure caused by the heat-generating electronic components being conducted to the display panel. Attached Figure Description

[0050] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0051] Figures 1-6 show schematic cross-sectional views of circuit boards with different structures according to the first embodiment of the present invention;

[0052] Figure 7 shows a schematic diagram of the structure of an externally driven heat dissipation unit according to another embodiment of the present invention;

[0053] Figure 8 shows a schematic diagram of the layer structure of the circuit board according to an embodiment of the present invention;

[0054] Figure 9 shows the top view projection relationship between the heat dissipation cavity and electronic components in an embodiment of the present invention;

[0055] Figures 10-12 show schematic diagrams of the display module according to an embodiment of the present invention;

[0056] Figure 13 shows a schematic diagram of the heat dissipation structure when the display module is set vertically. Detailed Implementation

[0057] To more clearly illustrate the present invention, the following description, in conjunction with embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0058] Based on the localized yellow spot defects that appeared in display products, the inventors, through extensive experiments and research, discovered the following reasons for the localized yellow spot defects in display products: The inventors found that the locations of the yellow spot defects were mostly in the circuit board area, and more precisely, in the locations of some heat-generating electronic components on the circuit board.

[0059] The inventors further discovered that high temperatures in local electronic components can affect the performance of OLEDs. Organic light-emitting materials are highly sensitive to temperature. Excessive local temperature can cause the light-emitting devices at the corresponding locations to decay too quickly, resulting in a decrease in brightness at the corresponding locations on the display panel. In addition, due to the inconsistent decay rates of the red, green, and blue pixels on the display panel, the displayed color in that area will change from normal to yellowish (due to excessive decay of blue pixels), and then to greenish (after the blue pixels have reached their decay limit, red decay becomes apparent), thus causing localized display defects.

[0060] Based on the above research, related technologies add thermally conductive or insulating materials to the PCB (Printed Circuit Board) below or above the location of heat-generating electronic components. However, this approach increases the overall space and presents material adhesion issues. The thermally conductive material can only adhere locally, and its actual contact with the PCB is poor due to the design limitations of various peripheral components. Therefore, this invention proposes a PCB, a manufacturing method, and a display module to solve these problems.

[0061] The first embodiment of the present invention provides a circuit board, as shown in Figures 1 to 8, wherein electronic components 30 are disposed on the circuit board 10, the circuit board 10 including a base layer 11, a plurality of trace layers 12 and a pin layer 13 stacked sequentially, and the circuit board 10 further includes a heat dissipation structure 14, the heat dissipation structure 14 including:

[0062] A heat dissipation cavity 141 that penetrates at least a portion of the plurality of wiring layers 12;

[0063] A first via 142 penetrates the pin layer 13 and extends in a direction opposite to the stacking direction to communicate with the first end of the heat dissipation cavity 141; and

[0064] The second guide hole 143 penetrates the pin layer 13 and extends in a direction opposite to the stacking direction to communicate with the second end of the heat dissipation cavity 141. The first end and the second end of the heat dissipation cavity 141 are arranged opposite to each other in the orthographic projection of the base layer 11.

[0065] Based on the heat dissipation structure 14 design of this embodiment, the connection structure between the first guide hole 142 and the heat dissipation cavity 141, and between the second guide hole 143 and the heat dissipation cavity 141 in this embodiment is a straight-through structure, that is, the first guide hole 142 and the second guide hole 143 are directly connected to the heat dissipation cavity 141 respectively. With this setting, the heat dissipation cavity 141, the first guide hole 142 and the second guide hole 143 constitute a heat dissipation path that can exchange airflow with the outside gas, thereby realizing the heat dissipation of the heat dissipation structure 14.

[0066] Furthermore, this embodiment of the invention designs the structure of the circuit board 10 itself and sets up a heat dissipation cavity inside the circuit board 10. The heat dissipation cavity 141 is used to achieve heat insulation between the electronic components and the display panel placed on the upper and lower sides of the circuit board 10 in the stacking direction. This embodiment does not set thermal conductive material on the outside of the circuit board 10. Therefore, the circuit board 10 of this embodiment does not sacrifice the overall space and there is no problem of external bonding of thermal conductive material. The internal structure of the circuit board 10 is designed directly to improve the display failure of the display panel caused by the heat of the electronic components being conducted to the display panel.

[0067] It is worth noting that the stacking direction described in the embodiments of the present invention is the structural direction from the base layer to the routing layer and to the pin layer, that is, the structural direction from bottom to top is the stacking direction. Furthermore, the structural direction deviating from the stacking direction described in the embodiments of the present invention is the structural direction from the pin layer to the routing layer and to the base layer, that is, the structural direction from top to bottom is the deviating direction from the stacking direction. The following description uses the stacking direction and the deviating direction of this embodiment.

[0068] In an optional embodiment, as shown in FIG2, the heat dissipation structure 14 further includes a first connecting channel 144 connecting the first guide hole 142 and the first end of the heat dissipation cavity 141. The first connecting channel 144 penetrates at least a portion of the wiring layers 12 corresponding to the heat dissipation cavity 141. The number of wiring layers 12 penetrated by the first connecting channel 144 is less than the number of wiring layers 12 penetrated by the heat dissipation cavity 141.

[0069] In this embodiment, the first guide hole 142 and the heat dissipation cavity 141 are not directly connected, but are connected through a first connecting channel 144. In this embodiment, the first connecting channel 144 at least penetrates a portion of the wiring layer 12 corresponding to the heat dissipation cavity 141. This means that, in the stacking direction, the height of the first connecting channel 144 is different from the height of the heat dissipation cavity 141. That is, the wiring layer 12 penetrated by the first connecting channel 144 and the wiring layer 12 penetrated by the heat dissipation cavity 141 have overlapping wiring layers 12. The number of overlapping wiring layers 12 is less than the number of wiring layers 12 penetrated by the heat dissipation cavity 141. Through this arrangement, the first connecting channel 144 can achieve a certain degree of connection. The channel 144 and the heat dissipation cavity 141 form a structure with a height difference. Based on the principle of air pressure, this height difference structure allows the air used for flow and heat dissipation to converge into the upper cavity space of the heat dissipation cavity 141 near the pin layer 13, compared to the straight-through heat dissipation structure 14 shown in Figure 1. Therefore, the volume of air used for heat dissipation in the heat dissipation cavity 141 is smaller than the cavity volume of the heat dissipation cavity, meaning that not all the air in the heat dissipation cavity 141 can be used for heat dissipation. In this embodiment, the heat dissipation structure 14 with a height difference between the first connecting channel 144 and the heat dissipation cavity 141 allows for a larger volume and stronger flow of air or medium, further improving the heat dissipation effect.

[0070] In another embodiment of this invention, as shown in FIG3, the first connecting channel 144 further penetrates a portion of the wiring layer 12 near the pin layer 13 until it connects with a portion of the wiring layer 12 corresponding to the penetrating heat dissipation cavity 141. With this configuration, the surface of the wiring layer 12 corresponding to the channel wall of the first connecting channel 144 away from the base layer 11 and the surface of the wiring layer 12 corresponding to the cavity wall of the heat dissipation cavity 141 away from the base layer 11 have a height difference. Furthermore, the surface of the wiring layer 12 corresponding to the channel wall of the first connecting channel 144 near the base layer 11 and the surface of the wiring layer 12 corresponding to the cavity wall of the heat dissipation cavity 141 away from the base layer 11 have a height difference. In other words, the heights of the first connecting channel 144 and the heat dissipation cavity 141 in the stacking direction are different in this embodiment of the invention, which makes the capacity of flowing air or medium larger, thereby improving the heat dissipation effect.

[0071] In another alternative embodiment, referring to the structural design of the first connecting channel 144 described above, as shown in FIG4, the heat dissipation structure 14 further includes a second connecting channel 145 connecting the second guide hole 143 and the second end of the heat dissipation cavity 141. The second connecting channel 145 penetrates at least a portion of the wiring layers 12 corresponding to the heat dissipation cavity 141. The number of wiring layers 12 penetrated by the second connecting channel is less than the number of wiring layers 12 penetrated by the heat dissipation cavity 141.

[0072] This configuration allows the second connecting channel 145 and the heat dissipation cavity 141 to form a structure with a height difference. Based on the principle of air pressure, this height difference structure allows for a larger volume of flowing air or medium, thereby improving the heat dissipation effect, compared to the straight-through heat dissipation structure 14 shown in Figure 1 where the air for flow and heat dissipation is located on the upper side of the heat dissipation cavity 141 near the pin layer 13.

[0073] In another embodiment of this invention, as shown in FIG5, the second connecting channel 145 further penetrates a portion of the wiring layer 12 near the pin layer 13 until it connects with a portion of the wiring layer 12 corresponding to the penetrating heat dissipation cavity 141. With this configuration, the surface of the wiring layer 12 corresponding to the channel wall of the second connecting channel 145 away from the base layer 11 and the surface of the wiring layer 12 corresponding to the cavity wall of the heat dissipation cavity 141 away from the base layer 11 have a height difference. Furthermore, the surface of the wiring layer 12 corresponding to the channel wall of the second connecting channel 145 near the base layer 11 and the surface of the wiring layer 12 corresponding to the cavity wall of the heat dissipation cavity 141 away from the base layer 11 have a height difference. In other words, the second connecting channel 145 and the heat dissipation cavity 141 of this invention have different heights in the stacking direction, resulting in a larger capacity for flowing air or medium, thereby improving the heat dissipation effect.

[0074] In another alternative embodiment, the heights of the first connecting channel 144, the heat dissipation cavity 141, and the second connecting channel 145 gradually increase in the stacking direction, either from the first guide hole 142 to the second guide hole 143 or from the second guide hole 143 to the first guide hole 142.

[0075] In one example, as shown in Figure 6, in the direction from the first guide hole 142 to the second guide hole 143, that is, in the rightward direction as shown in Figure 6, the height of the first connecting channel 144, the heat dissipation cavity 141 and the second connecting channel 145 gradually increases in the stacking direction, forming a heat dissipation cavity structure with gradually increasing steps. Through this setting, the capacity of flowing air or medium is further increased, thereby improving the heat dissipation effect.

[0076] In an optional embodiment, as shown in FIG11, the heat dissipation structure 14 further includes a heat insulation material 150 filling the heat dissipation cavity 141, the first guide hole 142, and the second guide hole 143. When the heat dissipation structure 14 further includes a first connecting channel 144, the heat insulation material 150 is also filled in the first connecting channel 144. In another embodiment, when the heat dissipation structure 14 further includes a second connecting channel 145, the heat insulation material 150 is also filled in the second connecting channel 145.

[0077] In this embodiment of the invention, the heat insulation material 150 includes one or more of heat insulation foam, graphene, or alumina. With this arrangement, the heat insulation material 150 fills the hollowed-out circuit board 10 to achieve a heat insulation effect in the stacking direction. For example, the display panel is disposed below the circuit board 10, that is, on the side of the base layer 11 away from the pin layer 13, and the electronic component 30 is disposed above the circuit board 10, that is, above the pin layer 13, and is connected to the corresponding pin.

[0078] Based on this embodiment, when the electronic component 30 generates heat during operation, the heat insulation material 150 filled inside the perforated circuit board 10 can block the heat transfer of the electronic component 30 to the display panel, thereby improving the heat insulation effect and further improving the display panel's poor display caused by the heat of the electronic component 30 being conducted to the display panel.

[0079] In an optional embodiment, as shown in FIG7, the heat dissipation structure 14 further includes:

[0080] A first flow guide tube 146 connected to the first guide hole 142 is located on the side of the pin layer 13 away from the base layer 11;

[0081] A second flow guide 147 connected to the second guide hole 143, located on the side of the pin layer 13 away from the base layer 11;

[0082] The heat dissipation fluid 148 filled in the heat dissipation cavity 141; and

[0083] The heat dissipation driving unit 149, which connects the first guide pipe 146 and the second guide pipe 147, is used to drive the heat dissipation fluid 148 to flow in the reflux structure formed by the heat dissipation cavity 141, the first guide hole 142, the first guide pipe 146, the second guide pipe 147 and the second guide hole 143.

[0084] The heat dissipation structure 14 described in this embodiment of the invention has a heat dissipation driving unit 149 and a guide pipe (first guide pipe 146 and second guide pipe 147) connected to each guide hole on the outside of the circuit board 10, and a heat dissipation fluid 148 is filled in the heat dissipation cavity 141. In a specific example, a highly fluid thermally conductive medium such as oleate can be filled in the heat dissipation cavity 141 to form a heat dissipation circulation loop, improve the heat dissipation effect, and further improve the display failure of the display panel caused by the heat-generating electronic components 30 being conducted to the display panel.

[0085] It is worth noting that the structural design of the heat dissipation driving unit 149, the first guide tube 146, and the second guide tube 147 in this embodiment is also applicable to the structure with the first connecting channel and the second connecting channel in the aforementioned embodiment. That is, the heat dissipation structure 14 in Figures 1-6 can also be applied to the design scheme of the external heat dissipation driving unit 149 in this embodiment. In this structure, the heat dissipation fluid 148 forms a return flow structure in the heat dissipation cavity 141, the first connecting channel 144, the first guide hole 142, the first guide tube 146, the second guide tube 147, the second guide hole 143, and the second connecting channel 145. Under the drive of the heat dissipation driving unit 149, the heat dissipation fluid 148 circulates in the return flow loop, thereby transferring the heat of the heated electronic component 30.

[0086] The above embodiments describe the cross-sectional structure of the heat dissipation structure 14. The circuit board 10 has a multi-layer structure, such as a structure design with a total of 8 or 10 film layers in related technologies. The following embodiments of the present invention design the layer structure of the circuit board 10. In an optional embodiment, as shown in FIG8, the pin layer 13 includes a plurality of pins 131. Electronic components 30 are disposed on the pin layer 13. As shown in FIG8, the pins 131 are arranged around the electronic components 30 to achieve the maximum number of pins 131.

[0087] In this embodiment, as shown in FIG8, the wiring layer 12 includes a connecting line layer 121, which includes multiple connecting lines that are respectively connected to the pins 131 of the pin layer 13. The connecting line layer 121 is separated from the connecting lines by through-holes formed by the heat dissipation structure 14. In a specific example, due to the limited area of ​​the pin layer 13, when there are a large number of connecting lines to the pins 131, signal transfer between different layers is achieved through multiple connecting line layers 121 and transition vias connecting different connecting line layers 121. This design optimizes the area of ​​the outermost pin layer 13, simplifying its structure.

[0088] In an optional embodiment, as shown in FIG8, the wiring layer 12 further includes:

[0089] A shielding layer 122 is disposed between adjacent pin layers 13 and trace layers 12, and / or between adjacent connection layers 121, and

[0090] Grounding layer 123 is set between two adjacent membrane layers.

[0091] Wherein, the orthogonal projection of the through hole formed by the heat dissipation structure 14 through the shielding layer 122 on the base layer does not overlap with the orthogonal projection of the shielding metal of the shielding layer on the base layer;

[0092] Wherein, the orthographic projection of the through hole formed by the heat dissipation structure 14 through the grounding layer 123 on the base layer does not overlap with the orthographic projection of the grounding wire of the grounding layer 123 on the base layer.

[0093] This embodiment further describes the structure of the wiring layer 12. A shielding layer is used to shield the signal between adjacent wiring layers 121 when there are multiple wiring layers 121. A grounding layer 123 is used to prevent electrostatic discharge. In this embodiment, the shielding layer is set between adjacent wiring layers 121, but the position of the grounding layer 123 is not limited. For example, the grounding layer 123 can be set between the pin layer 13 and the wiring layer 121, or between the wiring layer 121 and the shielding layer. Those skilled in the art can design according to actual applications, which will not be elaborated here.

[0094] In an optional embodiment, the base layer 11 serves as the ground layer 123, enabling the reuse of the layer structure.

[0095] In this embodiment of the invention, the number of each film layer in the wiring layer 12 is designed according to the actual application. For example, when the circuit board 10 is an 8-layer board or a 10-layer board or more film layers, the number of connecting line layers 121, shielding layers and grounding layers 123 in the wiring layer 12 is further designed according to the actual application.

[0096] In an optional embodiment, the first guide hole 142 and the second guide hole 143 are respectively disposed on opposite sides of the projection boundary of the heat dissipation cavity 141 on the orthographic projection of the substrate layer 11. This arrangement ensures the stability of the circulation loop of the heat dissipation path.

[0097] In another embodiment, as shown in FIG9, the first guide hole 142 is a plurality of air inlets arranged sequentially along the first direction, and the second guide hole 143 is a plurality of exhaust holes arranged sequentially along the first direction. That is, the plurality of first guide holes 142 and the plurality of second guide holes 143 are also designed on both sides, that is, guide holes of the same type are located on the same side of the projection boundary of the heat dissipation cavity 141 on the orthographic projection of the base layer 11. For example, the left vertical direction shown in FIG9 is entirely composed of first guide holes 142 for air intake, thereby ensuring a stable heat dissipation path.

[0098] In an optional embodiment, as shown in FIG9, the pin 131 is connected to an electronic component 30 fixed on the surface of the pin layer 13 away from the substrate layer 11.

[0099] The orthographic projection of the first guide hole 142 on the substrate 11 and the orthographic projection of the second guide hole 143 on the substrate 11 do not overlap with the orthographic projection of the electronic component 30 located between the first guide hole 142 and the second guide hole 143 on the substrate 11.

[0100] As shown in Figure 9, there are multiple first guide holes 142 and second guide holes 143, which are arranged sequentially in the same direction. In this embodiment, the first guide holes 142 and second guide holes 143 extend in the vertical direction shown in Figure 9. The first guide hole 142 is closer to the vertical boundary of the first substrate layer 11 than the electronic component 30 between the first guide hole 142 and the second guide hole 143. The second guide hole 143, which cooperates with the first guide hole 142, is closer to the vertical boundary of the first substrate layer 11 than the electronic component 30 between the first guide hole 142 and the second guide hole 143. That is, the orthographic projection of the first guide hole 142 on the substrate layer 11 and the orthographic projection of the second guide hole 143 on the substrate layer 11 are located outside the orthographic projection of the heat-dissipating electronic component 30 on the substrate layer 11, so as to avoid the first guide hole and the second guide hole 143 from conflicting with the pin 131 of the electronic component 30.

[0101] In this embodiment, when there are multiple pins 131 and multiple electronic components 30, different pins 131 are connected to the corresponding pins 131 of the electronic components 30. The pins 131 are bound to the corresponding pins 31 of the electronic components 30 to ensure transmission effect. Since the electronic components 30 are disposed on the pin layer 13, the ends of the first guide hole 142 and the second guide hole 143 are also disposed on the surface of the pin layer 13. Therefore, in this embodiment, the first guide hole 142 and the second guide hole 143 avoid each pin of the pin layer 13, and there is no interference between the guide hole and the pin 131 to avoid circuit crosstalk of the circuit board 10.

[0102] Based on the circuit board 10 design of the above embodiments of the present invention, the present invention designs the structure of the circuit board 10 itself and sets a heat dissipation cavity 141 inside the circuit board 10. The heat dissipation cavity 141 is used to achieve heat insulation between the electronic components 30 placed on the upper and lower sides of the circuit board 10 and the display panel in the stacking direction. In this embodiment, no heat-conducting material is set on the outside of the circuit board 10. Therefore, the circuit board 10 of this embodiment will not sacrifice the overall space and there is no problem of external bonding of heat-conducting material. The internal structure of the circuit board 10 is designed directly to improve the display failure of the display panel caused by the heat of the electronic components 30 being conducted to the display panel.

[0103] Another embodiment of the present invention provides a display module, as shown in Figures 10-12, the display module comprising:

[0104] Display panel 20;

[0105] A circuit board 10, as described in the first embodiment of the present invention, is bonded to the display panel 20. The circuit board 10 is fixed to the non-light-emitting side of the display panel 20 by a bonding part 15. The pin layer 13 is farther away from the display panel 20 than the substrate layer 11.

[0106] Multiple electronic components 30 are disposed on the display panel 20, and each pin 31 of the electronic components 30 is connected to the pin 131 of the pin layer 13.

[0107] For example, the display panel 20 shown in FIG10 of the present invention is applied to the circuit board 10 shown in FIG6 of the embodiment of the present invention; the display panel 20 shown in FIG11 is applied to the internally punched structure and the internally filled heat insulation structure shown in FIG6; the display panel 20 shown in FIG12 is applied to the circuit board 10 with an external driving heat dissipation unit shown in FIG7; the display panel 20 of the embodiment of the present invention is not only applied to the circuit board 10 shown in FIG6 and FIG7, but also to the circuit board 10 shown in FIG1-FIG5.

[0108] In the display module of this embodiment, the electronic component 30 is disposed on the non-light-emitting side of the display panel 20 at a position corresponding to the display area. Based on the circuit board 10 with heat dissipation structure 14 of this embodiment, the heat emitted by the electronic component 30 during operation can be blocked and dissipated, thereby improving the heat dissipation effect and further improving the display failure of the display panel 20 caused by the heat generated by the electronic component 30 being conducted to the display panel 20.

[0109] In an optional embodiment, the electronic component 30 includes one or more of a timing controller, a signal bridge chip, a memory chip, a power management chip, a thin-film driving transistor, or a crystal oscillator. That is, the heat dissipation structure 14 of this embodiment can be provided at the corresponding positions of the various types of electronic components 30 disposed on the circuit board 10.

[0110] Furthermore, the electronic component 30 in this embodiment of the invention includes, but is not limited to, the various components described above, such as a CPU assistant and a motherboard, which can be designed by those skilled in the art according to actual applications.

[0111] In an optional embodiment, as shown in FIG9, the orthographic projection of the heat dissipation cavity 141 onto the substrate 11 covers the orthographic projection of one of the electronic components 30 onto the substrate 11 or the combined projection formed by superimposing the orthographic projections of multiple components onto the substrate 11.

[0112] The display panel 20 of this invention can be applied to various display sizes, such as small-sized mobile phone products of 6 to 8 inches, medium-sized automotive and aviation entertainment display products of 12 to 20 inches, and even large-sized automotive elongated display products of 55 inches.

[0113] Based on the different sizes of display products, and considering the limited space of small-sized display products, when the display product is small, the orthographic projection of the heat dissipation cavity 141 on the base layer 11 covers the combined projection formed by the superposition of the orthographic projections of multiple components on the base layer 11. In other words, in this embodiment, multiple components are concentrated in one area, and a heat dissipation structure 14 with a large area is set in this area. That is, the area of ​​the heat dissipation cavity 141 is set to a large area to cover multiple components, so as to achieve heat dissipation of multiple components at the same time while ensuring that the overall heat dissipation space is not occupied.

[0114] In an optional embodiment, as shown in FIG13, the circuit board 10 is connected to a trace end located at one end of the display panel 20 via a bonding part 15 and folded to the non-light-emitting side of the display panel 20.

[0115] The first guide hole 142 is an air inlet, and the second guide hole 143 is an exhaust outlet. The second guide hole 143 is farther away from the wiring end of the display panel 20 than the first guide hole 142.

[0116] In this embodiment, the display panel 20 is generally arranged vertically, that is, the binding part 15 is arranged at the bottom. In order to satisfy the airflow principle, that is, hot air circulates upward, the first guide hole 142 is arranged at the bottom of Figure 13 and the second guide hole 143 is arranged at the top to realize heat dissipation according to the movement of gas when it is heated.

[0117] In an optional embodiment, as shown in FIG13, the display panel 20 is bonded to the bonding portion 15 of the circuit board 10 via the flip-chip film 21. The driver chip 22 is fixed to the side of the flip-chip film 21 facing the display panel 20 by the COF (Chip On Film) process. For example, adhesive 23 is provided on the flip-chip film 21 on both sides of the driver chip 22. On the one hand, the adhesive 23 fixes the flip-chip film 21, and on the other hand, the adhesive 23 protects the driver chip 22 disposed in the gap.

[0118] Another embodiment of the present invention provides a method for manufacturing a circuit board 10, the method comprising:

[0119] Multiple stacked wiring layers 12 are sequentially formed on the base layer 11;

[0120] The wiring layer 12 is patterned to form a heat dissipation cavity 141 that penetrates at least a portion of the wiring layer 12 in the plurality of wiring layers 12;

[0121] A pin layer 13 is formed on the side of the wiring layer 12 away from the base layer 11;

[0122] The pin layer 13 and the wiring layer 12 are patterned, and the patterned vias are extended to communicate with the first end of the heat dissipation cavity 141 to form a first via 142.

[0123] The pin layer 13 and the trace layer 12 are patterned, and the patterned vias are extended to communicate with the second end of the heat dissipation cavity 141 to form a second via 143. The first end of the heat dissipation cavity 141 and the second end of the heat dissipation cavity 141 are arranged opposite to each other on the orthographic projection of the substrate layer 11.

[0124] The first guide hole 142, the second guide hole 143, and the heat dissipation cavity 141 form a heat dissipation structure 14.

[0125] In the process of manufacturing the circuit board 10 in this embodiment, a heat dissipation cavity 141 is formed inside the circuit board 10 by patterning a portion of the film layer of the circuit board 10. A first guide hole 142 and a second guide hole 143 are formed on the surface and inside the circuit board 10. Through this arrangement, the heat dissipation cavity 141, the first guide hole 142 and the second guide hole 143 constitute a heat dissipation path that can exchange airflow with the outside gas, thereby realizing the heat dissipation of the heat dissipation structure 14 and improving the display failure of the display panel 20 caused by the heat-generating electronic components 30 being conducted to the display panel 20.

[0126] It is worth noting that specific embodiments of the manufacturing method of the circuit board 10 in this invention can be found in the circuit board 10 of the foregoing embodiments, and will not be repeated here.

[0127] In the description of this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0128] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A circuit board, characterized in that, The circuit board includes a base layer, multiple trace layers, and a pin layer stacked sequentially. The circuit board also includes a heat dissipation structure comprising: a heat dissipation cavity penetrating at least a portion of the multiple trace layers; a first via penetrating the pin layer and extending away from the stacking direction to communicate with a first end of the heat dissipation cavity; and a second via penetrating the pin layer and extending away from the stacking direction to communicate with a second end of the heat dissipation cavity. The first end and the second end of the heat dissipation cavity are positioned opposite each other on the orthographic projection of the base layer. The heat dissipation structure further includes a first connecting channel connecting the first via and the first end of the heat dissipation cavity. The first connecting channel penetrates at least a portion of the trace layers corresponding to the heat dissipation cavity, and the number of trace layers penetrated by the first connecting channel is less than the number of trace layers penetrated by the heat dissipation cavity.

2. The circuit board according to claim 1, characterized in that, The heat dissipation structure further includes a second connecting channel connecting the second guide hole and the second end of the heat dissipation cavity. The second connecting channel penetrates at least a portion of the wiring layers corresponding to the heat dissipation cavity, and the number of wiring layers penetrated by the second connecting channel is less than the number of wiring layers penetrated by the heat dissipation cavity.

3. The circuit board according to claim 1 or 2, characterized in that, The heat dissipation structure further includes a heat insulation material filled in the heat dissipation cavity, the first guide hole, and the second guide hole. When the heat dissipation structure further includes a first connecting channel, the heat insulation material is also filled in the first connecting channel; and / or when the heat dissipation structure further includes a second connecting channel, the heat insulation material is also filled in the second connecting channel.

4. The circuit board according to claim 1 or 2, characterized in that, The heat dissipation structure further includes: a first guide pipe connected to the first guide hole; a second guide pipe connected to the second guide hole; a heat dissipation fluid filled in the heat dissipation cavity; and a heat dissipation driving unit connecting the first guide pipe and the second guide pipe, for driving the heat dissipation fluid to flow in the return structure formed by the heat dissipation cavity, the first guide hole, the first guide pipe, the second guide pipe and the second guide hole.

5. The circuit board according to claim 1, characterized in that, The pin layer includes multiple pins; the trace layer includes a connecting line layer, which includes multiple connecting lines that are respectively connected to the pins of the pin layer, wherein the connecting line layer is formed by a through hole through the heat dissipation structure and avoids the connecting lines.

6. The circuit board according to claim 5, characterized in that, The trace layer further includes: a shielding layer disposed between adjacent pin layers and trace layers, and / or disposed between adjacent connection layers, and a grounding layer disposed between two adjacent film layers, wherein the orthographic projection of the through-hole formed by the heat dissipation structure through the shielding layer on the base layer does not overlap with the orthographic projection of the shielding metal of the shielding layer on the base layer; wherein the orthographic projection of the through-hole formed by the heat dissipation structure through the grounding layer on the base layer does not overlap with the orthographic projection of the grounding wire of the grounding layer on the base layer.

7. The circuit board according to claim 1, characterized in that, The first guide hole is a plurality of air inlets arranged sequentially along the first direction, and the second guide hole is a plurality of exhaust holes arranged sequentially along the first direction. The first guide hole and the second guide hole are respectively located on opposite sides of the projection boundary of the heat dissipation cavity on the base layer.

8. The circuit board according to claim 5, characterized in that, The pin is connected to an electronic component fixed on the surface of the pin layer away from the substrate layer; the orthographic projection of the first via on the substrate layer and the orthographic projection of the second via on the substrate layer do not overlap with the orthographic projection of the electronic component on the substrate layer.

9. A display module, characterized in that, The display module includes: a display panel; a circuit board as described in any one of claims 1 to 8 bonded to the display panel, the circuit board being fixed to the non-light-emitting side of the display panel, the pin layer being farther away from the display panel than the substrate layer; and a plurality of electronic components disposed on the display panel, each pin of the electronic components being connected to a pin of the pin layer.

10. The display module according to claim 9, characterized in that, The electronic components include one or more of a timing controller, a signal bridge chip, a memory chip, a power management chip, a thin-film driving transistor, or a crystal oscillator, wherein the orthographic projection of the heat dissipation cavity on the substrate layer covers the orthographic projection of one component of the electronic components on the substrate layer or a combined projection formed by superimposing the orthographic projections of multiple components on the substrate layer.

11. The display module according to claim 9, characterized in that, The circuit board is connected to the trace end located at one end of the display panel via a bonding part and folded to the non-light-emitting side of the display panel. The first guide hole is an air inlet, the second guide hole is an exhaust outlet, and the second guide hole is farther away from the trace end of the display panel than the first guide hole.

12. A method for manufacturing a circuit board as described in any one of claims 1 to 8, characterized in that, The method includes: sequentially forming a plurality of stacked trace layers on a substrate layer; patterning the trace layers to form a heat dissipation cavity that penetrates at least a portion of the plurality of trace layers; forming a pin layer on the side of the trace layers away from the substrate layer; patterning the pin layer and the trace layers, forming a patterned via that extends to communicate with a first end of the heat dissipation cavity to form a first via; patterning the pin layer and the trace layers, forming a patterned via that extends to communicate with a second end of the heat dissipation cavity to form a second via, wherein the first end and the second end of the heat dissipation cavity are disposed opposite each other on the orthographic projection of the substrate layer; the first via, the second via, and the heat dissipation cavity form a heat dissipation structure.

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